Freewheeling synchronizer

Abstract

A freewheeling synchronizer for a power transmission device includes a clutch race rotationally fixable to a component of the power transmission device, and a synchronizer hub disposed radially outwardly of the clutch race and unidirectionally rotatable relative to the clutch race. The clutch race and synchronizer hub are freewheelable relative to one another.

What is claimed is: 
     
       1. A freewheeling synchronizer for a power transmission device, comprising:
 a clutch race having an inner periphery, rotationally fixable at the inner periphery to a component of the power transmission device; the clutch race including an outer periphery with unidirectional clutching elements, the outer periphery configured to support a synchronizer hub; 
 the synchronizer hub disposed radially outwardly from the clutch race and unidirectionally rotatable relative to the clutch race; 
 wherein the synchronizer hub includes an outer periphery with at least one pocket with a strut configured to engage both in the pocket and with a first synchronizer ring, the first synchronizer ring configured to frictionally engage a second synchronizer ring, and the strut configured to engage both in the pocket and with a third synchronizer ring, the third synchronizer ring configured to frictionally engage with a fourth synchronizer ring; 
 wherein a first gear is positioned on one side of the clutch race and a second gear is positioned on a second side of the clutch race and the clutch race is selectively engageable with either the first gear through the first and second synchronizer rings or the second gear through the third and fourth synchronizer rings; 
 wherein the clutch race includes a splined inner diameter, and an outer ratchet diameter defining a plurality of notches; 
 further comprising at least one pawl disposed between the clutch race and the synchronizer hub for engagement with the notches of the clutch race; 
 further comprising at least one spring to urge the at least one pawl into engagement with the notches of the clutch race. 
 
     
     
       2. A dual clutch transmission comprising:
 a first input shaft coupled to a first input clutch; 
 a second input shaft coupled to a second input clutch; 
 a first input gear coupled to the first input shaft; 
 a second input gear coupled to the first shaft; 
 a counter shaft offset from the input shafts; 
 a first gear freely rotatable on the counter shaft and in constant mesh with the first input gear; 
 a second gear freely rotatable on the counter shaft and in constant mesh with the second input gear; 
 a clutch race rotationally fixable at an inner periphery to a component of the power transmission device; the clutch race including an outer periphery with unidirectional clutching elements, the outer periphery configured to support a synchronizer hub of a synchronizer; 
 the synchronizer hub disposed radially outwardly from the clutch race and rotatable relative to the clutch race in only one direction; 
 wherein the synchronizer hub includes an outer periphery with at least one pocket with a strut configured to engage both in the pocket and with a first ring, the first ring configured to frictionally engage a second ring, and the strut configured to engage both in the pocket and with a third ring, the third ring configured to frictionally engage with a fourth ring; 
 wherein the first gear is positioned on one side of the clutch race and the second gear is positioned on a second side of the clutch race and the clutch race is selectively engageable with either the first gear through the first and second rings or the second gear through the third and fourth rings; 
 wherein the counter shaft and clutch race are freewheelable relative to the synchronizer hub during a transmission upshift to allow both input clutches to be simultaneously fully applied with the input clutches not slipping during at least part of the transmission upshift so that the counter shaft and the clutch race rotate faster than the synchronizer hub through the unidirectional clutching element; 
 wherein the synchronizer is configured such that when the first input clutch is transmitting power, a power path of the second input clutch through a given gear may be freely synchronously changed to a different selected gear.